


Dimension Dragon

by DShadow101



Category: Hyperdimension Neptunia, RWBY
Genre: Action, Blood, Comedy, F/F, Fluff, Gen, Light Sadism, Mild Gore, Other Additional Tags to Be Added, Violence
Language: English
Status: In-Progress
Published: 2020-04-18
Updated: 2020-04-18
Packaged: 2021-03-01 23:42:20
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,717
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23716120
Author URL: https://archiveofourown.org/users/DShadow101/pseuds/DShadow101
Summary: Takes place after Re;Birth3's true ending.After defeating Hyper Dimension Rei Ryghts, everything went back to normal for both the Hyper and Ultra dimensions. However, their peace is disrupted by an unexpected newcomer from an entirely different world.
Relationships: IF/Vert | Green Heart, Neptune | Purple Heart/Noire | Black Heart
Kudos: 1





	Dimension Dragon

**Author's Note:**

> Hey everyone. So sorry for the inactivity here in Ao3, just been busy with my other social media and also staying safe in quarantine. I apologize for still not updating RWBY GH since August of last year, I'm just lacking motivation to write the next chapter but I will write when I do get motivated. For now, I present y'all my new xover fic between RWBY and a fave game and fandom that I do love so much, Hyperdimension Neptunia.
> 
> I HIGHLY recommend you all watch all three Re;Birth gameplays of the Hyperdimension Neptunia series to understand this fic's current chronological time.
> 
> Once again, not a pro but I try my best.

After stopping the Rei of the Hyper dimension from destroying both the Hyper and Ultra dimension, and the creation of a permanent gateway between the Hyper and Ultra dimension, everything went back to normal for both worlds.

All respective CPUs continuing their duties, with Neptune getting encouragement from her Histoire to work more than just always slacking off and playing video games. While Neptune was reluctant to do it, she has been doing well with her duties as a CPU of Planeptune.

This surprised the other CPUs to a degree as they heard news of Purple Heart working a lot more than she usually does. They were happy to say the least that Neptune is acting like a proper CPU to her nation, as she is usually lazy and taking frequent naps.

It was also a relatively peaceful and sunny day for the entirety of Gamindustri, with all of its nations working to keep their shares up and stabilized.

With the permanent gateway, many have already crossed over from both worlds, mainly the CPUs and even the CPU candidates to see how their older siblings look like in the Ultra dimension.

Needless to say, everyone has been enjoying new company from both worlds, especially the two CPUs of Planeptune despite getting scolded by both of their Histoires.

Speaking of the two goddesses, the two are currently in Neptune’s Basilicom in her nation of Planeptune getting news from Neptune’s Histoire about a strange reading of energy just south of Lowee. Peashy was also there with the two CPUs.

Both she and Plutia’s Histoire have deduced that it could be another possible gateway to another dimension, and that they sense a massive signal of energy within the gateway which could potentially lead to a new person crashing into the Hyper dimension.

Neptune put a finger to chin as she hummed. “Should we be really be worried about another gateway Histy? I mean, the dimension connecting to ours seems pretty normal and nothing bad has happened yet ever since we defeated Rei.”

“I agree with Neppy. Everything’s been sooo peaceful after that whole incident.” Plutia adds.

“Me too! I agree with Neptuna.” Peashy says giddily.

Histoire sighs at this. “We cannot simply ignore this strange and unknown energy you three. Both of our worlds have their own version of enemies and what I can remember they have done quite a lot of trouble for both worlds. This possible gateway could be the result of another dimension connecting to ours, and the culprits could that world’s version of our respective enemies. We cannot ignore this gateway and you two will go there and investigate.” Histoire explained sternly.

“Aww. Can I come too Neptuna? I can go big like all of you and I can handle fighting.” Peashy then asked.

“Of course you can P-Ko.” Neptune answers with a smile and a gentle pat to Peashy’s head.

“Please watch over her you two.” Histoire reminds.

“Don’t worry Histy. We won’t take our eyes off her for even a moment.” Plutia calmly reassures with a smile of her own.

All three then proceed out of the Basilicom and out into its balcony.

“Oh. By the way Plutie. As always, no transforming until a situation comes when you really need to.” Neptune cheerily reminds.

“Aww. You’re a meanie Neppy.” Plutia replies with a sad tone, with Peashy giggling instead. “We’ll just go big and carry you with us Plutie.” The youngest girl reassures.

Both Neptune and Peashy activate HDD, in their goddess forms appearing much older and more mature in personality, except for Peashy as always.

Purple Heart and Yellow Heart grab Plutia by one hand and all three proceed to the place Histoire was talking about thanks to her giving the specific location.

While in the air, Plutia asks Purple Heart. “What do you think this new gateway could be Neppy?”

“Judging by how Histoire explained it, she might be right on that new gateway being a result of another dimension connecting to ours. And it could potentially be a gateway opened by another version of our enemies on either side.” Purple Heart replies.

“Do you think bad guys will actually come out of the gateway Neptuna?” Yellow Heart then asked.

“We’ll find out in due time P-Ko. For now, let’s be prepared for any possibility once we arrive.” Purple Heart replies.

“So, does that mean I can transform if a bad guy does come out Neppy?” Plutia then asked in a hopeful tone.

“As much as I have the barest concern if an enemy arrives, you can Plutie.” Purple Heart replies reluctantly.

“Yay!” Plutia said happily as the three of them got closer to their destination.

They pass by the nation of Lowee, arriving to a snowy forest area where Histoire’s navigations lead them. Purple Heart and Yellow Heart slowly descend down, letting Plutia go as their feet touched the ground.

“In any chance a gateway opens, be ready for anything that will come out from it.” Purple Heart says sternly, receiving replies of approval from Yellow Heart and Plutia.

As if on cue, Purple Heart sensed a massive amount of energy from above them, causing her to look up to the sky and seeing a dimension gate appear.

“P-Ko, Plutie, get ready.” Purple Heart says as she summoned her blade, with Peashy taking a fight stance and raising her large claw gauntlets, and Plutia activating HDD and transforming to the much more sadistic and more dominating Iris Heart, her own weapon of a whip that can connect to become a sword.

The gateway that was now open then emits an echoing sound of a person screaming, making the three CPUs tense up, gripping their weapons more tightly.

The screaming gets louder after a few moments, before a person comes crashing down to the area just a few meters away from the CPUs head first, causing rocks and dirt to launch in the air.

The gateway above the sky immediately closes moments after.

“Well that was a real rough landing.” Yellow Heart says innocently.

“Who could possibly be this newcomer of ours little Neptune?” Iris Heart asks in her usual seductive voice.

“I don’t know. Let’s go and see.” Purple Heart replies, the three CPUs floating up to where the new person landed.

They saw a body with its head buried on the ground, and they can see the person trying to dislodge their head from the dirt while emitting muffled grunts.

The person was wearing some kind of long dark coat with gold trimming, a dark turquoise scarf with a scale like pattern, and what seems to be an actual tail poking in between the coat.

The coat had long sleeves covering both arms. They also wore a dark turquoise scarf with a scale like pattern.

The tail was the same color as the coat, with a fur lining ending in a tuft, both colored an indigo blue color. The tail had two sharp prongs, one on either side just before the tuft.

They can see the person has spiky and long indigo blue hair, before the person finally manages to dislodge their head away from the dirt before they tumbled backwards and landing on their rump with a loud groan as they rubbed their head.

The three CPUs finally see the person’s face and more of their body, having tan skin, a purple shirt underneath the coat, a turquoise sash tied over the coat, green pants, and strangely a pair of clawed feet. They also had strangely dark colored ears that poked out of their hair from the side.

The person also seems to be around the age of 10 judging by their body structure.

Not only that, they can see the person has unusual eyes. The both had a black sclera with a golden yellow iris and a normal circular pupil, and a pair of small purple horns on their head.

As for the person’s gender, judging by the flat chest, they assume it’s a boy.

(Her height is about 5'0.)

“Aughh. Talk about a legit crash landing.” The person said with a deep voice, abnormal for a person his age.

“He doesn’t look like a bad guy Neppy. Look he does not have any weapons with him.” Yellow Heart points out.

“I’m afraid Plutie doesn’t think so P-Ko.” Purple Heart remarks as her Ultra Dimension counterpart made her way to the still groaning stranger.

Iris Heart wordlessly points the sharp tip of her blade in just an inch away from the stranger’s face as they finally managed to focus. Upon seeing the blade right in front of their face, they immediately backed away in a panic, scrambling a distance away from Iris Heart.

This made Iris Heart giggle rather darkly. “How did such a poor soul like you end up in this world?” she asked.

“World? Wait.. no.. it can’t be possible.” The stranger then mutters at the end as they looked to be in denial of his situation.

“Plutie hold on. We mustn’t harm them; I don’t sense anything negative about our newcomer.” Purple Heart then intervenes with Yellow Heart following behind.

“You always ruin my fun even in these forms little Neptune.” Iris Heart whines lightly.

“I assume that you don’t know the existence of other worlds.” Purple Heart then says to the stranger, who dusted themselves as they stood up at full height.

“It seems so. I am sorry if I’ve caused any kind of trouble. Before I forget, my name is Skias Drago, but please call me Sky for convenience.” Sky now introduced himself. “And also I may look like a boy, but I’m more of an Intersex. So please call me by girl pronouns if you will.” Sky added calmly.

All three CPUs were at ease as they felt nothing negative from Sky, and they could sense that this conversation would be fairly safe for all four of them.

“An Intersex? I’ve never heard of such a term.” Iris Heart remarks.

“Me neither Plutie.” Purple Heart agrees.

“What is exactly an Intersex Sky?” Yellow Heart then asks.

“It basically means being a boy and a girl all in one body.” Sky answered the best she can.

“That seems pretty self-explanatory.” Purple Heart comments.

“That seems weird though.” Yellow Heart said.

Iris Heart hums before she reverts back to her human form. “Well, at least the gateway that brought you here closed off quite quickly.” Plutia remarked.

“Seems we really had nothing to worry about then. We should head back to the Basilicom so we can discuss how you ended up here in our world.” Purple Heart then states.

Sky sighs. “Alright then. I have _so_ many questions already.”

Purple Heart and Yellow Heart carried Plutia and Sky respectively back to Planeptune’s Basilicom. When they arrived outside, they saw the other three CPUs of the neighboring nations, as well as all the CPU Candidates with Compa and IF.

Both Purple Heart and Yellow Heart deactivate HDD, before they were approached and asked who is the person they had with them. Neptune told all of them to discuss it inside the Basilicom so Histoire will be reassured that the gateway that Sky came from closed immediately after she landed.

Everyone was silent as they made their way inside the Basilicom, until they finally arrived to see Histoire.

“Hey Histy. Guess who we found?” Neptune said happily as she gestured to Sky, who was a bit taller than the human form CPU by a few inches.

Histoire went for a closer look. “Oh. Could he be the person that fell from the gateway?”

“Sure is Histy. And the gateway quickly closed afterwards so I think we don’t have to be worried about another dimension connecting to ours.” Plutia adds happily.

“Hmm. I wouldn’t say that exactly.” Noire intervenes.

“Even if the gateway closed afterwards, its still a result of another dimension gaining access to ours.” Blanc adds.

“Who knows when will that gateway open again? If we compare it to the normal gateway me and Neptune used, it can be opened twice and once it closes the second time, it could open in another three years.” Vert explains.

“I have the same feeling as well. I’ll investigate the energy levels I detected from the brief moment the gateway opened later on. For now, let us get to know our new guest here.” Histoire says. “I’m sure he has quite a lot of things he needs to know about our dimension.”

“Actually, miss Histoire, I am a She.” Sky then points out with a sheepish smile.

Everyone except for Neptune, Plutia, and Peashy widened their eyes upon hearing Sky’s statement.

“How is that even possible?” Nepgear asked.

“Ladies, I am something what is called an Intersex.” Sky deduces.

Sky took a while to explain to everyone what an Intersex means. Most of them understood what Sky is except for Rom and Ram much like Peashy due to their younger age.

It was Sky’s turn to ask what exactly is the world she has stumbled in quite surprisingly.

The CPUs of the four nations were more than willing to tell every information Sky needs to know about the Hyper Dimension. In the end Sky managed to get a basic understanding of the world as a whole.

“So, you four rule your respective nation as Goddesses, and you all need this energy called Share Energy for your nations to remain stable am I correct?” Sky then asked.

“Yup yup.” Neptune said giddily.

“That’s the whole idea.” Vert followed.

“Now that explains the forms I saw Neptune, Plutia, and Peashy all took when they saw me crash land.” Sky then remarked. “If you all don’t mind, can you show me you three’s HDD forms as well?” Sky then asked curiously.

Noire, Blanc and Vert all stood back a bit, before they shifted to their own goddess form. Needless to say, Sky can truly see the dramatic change in appearance and personality.

“Quite impressive I may say.” Sky commented, with the three CPUs all shifting back to their human forms.

“Now that we’ve done our part, its our turn to ask you questions.” Noire then points out.

“First and foremost, what world are you from?” Blanc asked.

“I hope you can all believe what I’m about to tell all of you.” Sky said with a smile, before she began her explanation of her world, which was called Remnant, and the specific Kingdom or Nation by this world’s term that Sky lives.

Everyone had quite the reactions to Sky’s home, most especially about the existence of magic and also the fact that Sky is an actual dragon that can take on a human form much like them.

All the CPUs and CPU candidates were all fascinated and interested in what Sky can do if she still possesses her original powers.

“So that explains your unique anatomy and body.” Blanc remarks.

“Say, could you still possess some of your powers from your home world?” Histoire then asked.

“Hmm. Let’s see.” Sky said before taking a deep breath and snapping her fingers, making her disappear completely in a flash.

“She’s gone!” Neptune exclaimed as the others all had wide eyes.

“I’m right behind Vert actually.” Sky said, making Vert jump slightly.

“Oh my.” Vert says.

“Seems you have retained your powers after all.” Blanc points out, seeing Sky teleport multiple times within the room as she appeared and disappeared from every corner, before eventually staying on the spot she once stood on in the beginning.

“That’s so cool!” Peashy said happily.

“Can you do tricks?” Rom and Ram then asked giddily, making Sky smile. “I have lots of them little ones.” Sky replied happily.

Sky showed quite the show for Rom, Ram, and Peashy. From creating astral projections of animals, to changing the hairstyles of Neptune, Plutia, Peashy, Noire, Blanc and Vert into that of their CPU forms, and even transforming Uni and Nepgear into several kinds of animals.

By the end of Sky’s show, everyone all seemed entertained from the display of Sky’s magic. “You should get a job as a magician here Sky.” Noire says playfully, making the dragon chuckle.

“I won’t exactly say I’m a simple magician Noire.” Sky replies.

“Sky, is this what you exactly look like in your world?” Vert then asked, getting Sky’s attention.

“Actually no. The possible reason why I’m in this form could be because of your world’s rule that when one is a goddess or someone that possesses such immense power must have a more dormant form to not exert that much power.” Sky quickly deduced.

“Could you try and transform much like how Neptune and the others do? Maybe you could take on what you truly look like in your world.” Histoire then suggests,

“Possibly. Although may I ask how tall is this room’s ceiling before I do that.” Sky then asked Histoire.

“Its about 8 ft Sky. Why ask?” Histoire replies.

“My true form is quite tall than even Vert when in her HDD form I will say.” Sky says amusingly before she closed her eyes and started to concentrate, everyone going silent to watch.

Before long, Sky’s entire body glowed light blue, and she started to grow. Her body changed and they noticed Sky’s horns extending as she grew taller and gained more muscle. Sky didn’t stop until she towered over everyone in the room, before she stopped.

The blue light fades, and Sky opened her eyes as her true self was now revealed. Needless to say, Sky had quite the change herself. More mature body, more muscle, sharper features, and more prominent dragon qualities, and also being much taller than even Vert.

Not only that, her left eye had become cybernetic and her right eye’s pupils becoming slit, her ears and horns showing visible missing portions, and scars appeared on Sky’s face; two across her left eye and two on her right cheek.

Sky’s clothing has also changed. Her coat was now split into two tails with tattered ends, and the right sleeve completely gone, showing Sky’s right upper arm sporting more scars.

On Sky’s right forearm she now wore a dark blue gauntlet with a crystal that has the image of a dragon’s head. Her sash changed from violet to green, and her feet now marked with several scars.

Sky’s tail prongs also showed missing portions. And finally, a massive sword was strapped to Sky’s back.

(Her height is about 6'7. :3.)

“Whoa.” Blanc could only say as Sky had to kneel down to be in eye contact with the much shorter group.

“So who has a more dramatic change?” Sky’s deeper and more edged voice then said.

“You sure are more handsome and taller like this Sky.” Plutia said with a smile. “I might make a doll out of you later on.”

Sky chuckles, the rest looking over her new body. “That would be sweet of you Plutie.”

“Whoooaaa. You’re really big Sky.” Peashy then remarks.

“You could be approximately over 6 feet in height.” Nepgear adds.

“And you seem to have experienced quite a lot of battles with all of your, scars.” Vert said hesitantly.

“Its quite alright Vert. I wear them with pride.” Sky reassured.

Sky then reverts back to her more dormant form. “While I like being my true self, its safe to say that being in my child form is more convenient.”

“Back to the matter at hand however. How did you exactly manage to be transported into our world?” Histoire then asked, getting back on track.

Sky became serious. “I don’t exactly know how and why I even ended up in this world.” The dragon replied as she sat down on one of the sofas. “I’ve never heard of other worlds until now, and the last thing I remember was being suddenly sucked into a random portal right in front of me.”

“But who could’ve opened a portal connecting ours to yours?” Histoire then points out.

Everyone became tense at that. “You don’t think,” Nepgear then starts. “One of the Seven Sages again from either of our dimensions?” Uni finished for her.

“Who could possibly even do such a thing without the help of someone like Histy?” Neptune then remarks.

“Hmmmmm…” Plutia hummed with her eyes closed for a moment before opening them.

“Can it be Darksty?” Compa then suggests.

“But she has told before that she can travel between dimensions, never anything regarding of being able to open a portal herself.” Noire then explains.

“However, she is someone who is a lot like Histoire from both of our dimensions.” Blanc then says seriously.

“And if she’s anything like either of them, then she might have found her own way of creating a portal to another dimension or world.” Vert adds.

“I agree with all of you. Croire could be capable of opening a portal much like myself and my counterpart in Plutia’s dimension. And if this is Croire we’re talking about, she might just be creating more entertainment for her to watch and enjoy.” Histoire explained with a bit of a deadpan tone at the last sentence.

“She _did_ cause the last occasion of our worlds’ almost ending by working with both Rei Ryghts, and it was double the trouble for all of us.” Noire says, reminiscing of the disaster they prevented.

“For someone so small, she can really create big disasters.” IF adds.

“We must locate Croire if we want answers to why she would bring Sky into our world.” Nepgear then says.

“But where could she even be after all that’s happened?” Uni then asks.

“Myself and my counterpart in the other dimension could work together to find traces of Croire’s unique energy waves and track her down if we manage to get any leads.” Histoire then answers.

“Well, now that’s settled, I think we should go introduce Sky to our nations in both dimensions.” Neptune then suggests with a smile.

Everyone all agreed, with Sky smiling as Neptune offered to give a tour of Planeptune since Sky was already in the Basilicom.

The other CPUs and CPU candidates all went back to their respective nation to resume their duties, with IF and Compa going out as well to do their jobs within Planeptune.

Before they went out however, Sky casted a spell on herself that would make her look like a normal person without all her dragonic features when people other than Neptune, Nepgear, Plutia, and Peashy will see. The three CPUs and CPU candidate accompanied Sky as they introduced the nation of Planeptune as a whole to their new foreign friend.

Sky enjoyed seeing the advanced land as she took in all the sceneries around her, most especially the park. The day came to a close as the group went back to the Basilicom just after the sun had set.

IF and Compa were already back themselves, and the two worked together to make dinner for all, which were just flank stakes with a few vegetables. As they ate on the table, Neptune turned to Sky and asked cheerily. “What do you think of Planeptune Sky?”

“Quite a beautiful nation you are governing Neptune. Most especially with how advanced your technology is compared to my own world.” Sky said with a smile after swallowing some of her meat.

“From what you’ve told us about your world, your kind seem to be not caught up with modern technology. Like your scrolls for example.” IF then comments.

“I also remember you saying that the nation Atlas seems to be the only one that have more advanced tech compared to the other kingdoms you mentioned too.” Compa adds.

“It took me and my friends a while to get used to using a scroll. Which can be a phone here in your world. But Compa you’re right on Atlas having more advanced tech compared to the others. They have all kinds of military robots, even huge ones called Paladins that can really wreck you up if you’re not agile and strong enough.” Sky confirms.

“Oooooh. They seem to be pretty strong then. Have you ever fought one before Sky?” Plutia then asked curiously.

“I’ve destroyed quite a few actually.” Sky said sheepishly, everyone’s eyes widening at that, except for Peashy who seem to enjoy her meal more than paying attention to the current conversation.

“On a scale of one to ten Sky, how much will you bet if you were to go up against me, Nep Jr, Plutie, P-Ko, Uni, Rom, Ram, Noire, Blanc, and Vert in a one on one battle whichever you would pick?” Neptune then asked.

“Hmmm. Ten.” Sky said confidently with a smile. Neptune and Plutia looked at each other for a bit before both smiled, with Nepgear only staying silent with wide and concerned eyes as her sister looked at Sky with her cocky smile.

“That’s quite confident of you to declare Sky, and you haven’t even seen me, Plutie, Nepgear, and P-Ko in battle yet. As a fair fighter, I’d allow you to see us all first in combat before we challenge you to an all-out fight.” Neptune then declares.

Peashy then perked up, having been listening to Neptune just a short while ago. “Whoa. You seem to be really strong if you wanna fight aaall of us Sky.” The child then said cheerily.

“I’m looking forward to our fight in the future.” Plutia said happily with her eyes closed.

“Uuuuhh… as much as I would disagree with my sister on fighting you someday, it’d be interesting to see how you fight Sky.” Nepgear could only say sheepishly.

“I can say the same myself.” Sky replied with a smile.

The group eventually finished their dinner, washed the dishes and cleaned the table. Now it was time for bed, despite Neptune and Peashy’s protest on wanting to play some late-night games, but Histoire much like a mother sternly says no and tells them once again to go to bed for Neptune will still have to work tomorrow with her CPU duties.

The Basilicom has extra bedrooms and Sky was given the one just beside the main bedroom where Neptune, Nepgear, Plutia, and Peashy all shared together.

The CPUs and CPU candidate along with IF and Compa all went to their respective bedrooms and Sky going to her new room after turning off all the lights within the Basilicom.

The dragon asked if she can use the bathroom to shower after a long day of walking around Planeptune, and Histoire was happy to escort Sky to where the Basilicom’s bathroom was stationed, and Sky happily took a shower after thanking Histoire.

Sky took in her new bedroom, which was quite decent enough for one person. A full wardrobe closet, even a coat rack. Sky gave a sigh before she removed her scarf and hanging it on the coat racket. Concentrating, her clothes changing to a set of purple pajamas with white chibi dragon heads printed all over.

Thanks to Sky’s unique magic, she didn’t really need to wear actual clothing, for she can manipulate her body fur and turn them into any kind of clothes of her choice without needing to wear real wardrobe. The only exception being her scarf, for it was a gift by her grandfather and Sky always wore it except when she's about to rest for the day.

Sky then lied down on the bed and thought about her current situation. She was stuck in a whole new world, with no way of getting back home; at least until Histoire finds a way to open a gateway back to her world.

Now Sky was immensely worried about what her friends and family are doing right currently to try and find her the best they can. And, with different worlds, it could mean that the way time works in the Hyper dimension is different from Remnant’s.

One minute in this world could be one day or even one month in Remnant, and Sky worried about it even more. Hopefully, she would get back home without much of a change when she manages to return to Remnant. For now, however, Sky needed to rest and go about a new day tomorrow.

With a final tired sigh, Sky pulled the soft blanket over herself, and drifted into slumber.

**Author's Note:**

> Story, Skias Drago Oc, and featured arts all owned by: Me
> 
> RWBY owned by: RT and Monty Oum
> 
> Hyperdimension Neptunia owned by: Idea Factory


End file.
